Head: Large, wide, black and shiny, not hairy. Yellow line across back of head. Lower face (clypeus) yellow on both male and female. Female mandibles entirely black, male mandibles yellow with black tips.
Thorax: Black, rough (punctured). Segment 1 (scutum) has yellow stripe on each shoulder pad (humeri). Another tiny spot on inside edge of wing knobs (tegulae). Segment 2 (scutellum) is raised with a yellow oblong mark each side of center. Thorax sides have somewhat raised, yellow tubercles very close to wing knobs (tegulae). Both male and female have small tuft of white hair below wing base.
Wings: Wing knobs (tegulae) reddish-brown. Wings long, dark. Base light. A lighter spot near wing tip.
Legs: Thighs (femora) mostly blackish. Shins (tibiae) yellowish-red (lighter on male) with a black stripe. Feet slightly darker. Male has long white fringe on underside of all legs.
Abdomen: Black, rough, short. Marks are yellow:
Segment 1: round patches at each side edge.
Segment 2: wide, arched stripe, narrowly interrupted at center.
Segments 3 to 5: paired squarish marks close together, each side of center. Male also have tiny yellow spot at each side edge.
Segment 6: Black on female.
Male (6 & 7) has thin yellow stripe at segment end.
Underside of female covered with dense whitish hair (pollen basket or scopa).
Underside of male has tufts of white hair along side edges.
Note: Females have yellow line across back of head, males do not.
Similar Species: Paranthidium jugatorium, both male and female have top of thorax completely surrounded with a yellow border.
hair and yellow mandible on male.
Size: 7 to 8 mm.
Habitat: Forest edges and meadows.
Food: Flower nectar and pollen.
Flight Time: July – August.
Life Cycle: Nests are made of resin and constructed above ground, usually on stumps or dead wood. Nest found on new growth of Scots Pine (Pinus sylvestris) had adult emerge a few days later. Thus, must have 2 generations per year.
Blister Beetle Nemognatha species larvae attach themselves to Anthidiellum bees when they visit flowers and then transported back to the nest. The beetles feed on the pollen/nectar mix stored for the bee’s young.
Chalcid Parasitic Wasp Monodontomerus minor may be a parasite.
Comments: Essex, Brant, Peel, Halton and Niagara.
For information on synonyms, references and type specimens see next page